Genetic regulation of carnitine metabolism controls lipid damage repair and aging RBC hemolysis in vivo and in vitro.

ABSTRACT: Recent large-scale multiomics studies suggest that genetic factors influence the chemical individuality of donated blood. To examine this concept, we performed metabolomics analyses of 643 blood units from volunteers who donated units of packed red blood cells (RBCs) on 2 separate occasions. These analyses identified carnitine metabolism as the most reproducible pathway across multiple donations from the same donor. We also measured l-carnitine and acyl-carnitines in 13 091 packed RBC units from donors in the Recipient Epidemiology and Donor Evaluation study. Genome-wide association studies against 879 000 polymorphisms identified critical genetic factors contributing to interdonor heterogeneity in end-of-storage carnitine levels, including common nonsynonymous polymorphisms in genes encoding carnitine transporters (SLC22A16, SLC22A5, and SLC16A9); carnitine synthesis (FLVCR1 and MTDH) and metabolism (CPT1A, CPT2, CRAT, and ACSS2), and carnitine-dependent repair of lipids oxidized by ALOX5. Significant associations between genetic polymorphisms on SLC22 transporters and carnitine pools in stored RBCs were validated in 525 Diversity Outbred mice. Donors carrying 2 alleles of the rs12210538 SLC22A16 single-nucleotide polymorphism exhibited the lowest l-carnitine levels, significant elevations of in vitro hemolysis, and the highest degree of vesiculation, accompanied by increases in lipid peroxidation markers. Separation of RBCs by age, via in vivo biotinylation in mice, and Percoll density gradients of human RBCs, showed age-dependent depletions of l-carnitine and acyl-carnitine pools, accompanied by progressive failure of the reacylation process after chemically induced membrane lipid damage. Supplementation of stored murine RBCs with l-carnitine boosted posttransfusion recovery, suggesting this could represent a viable strategy to improve RBC storage quality.

Spectroscopic Signature of Red Blood Cells in a D-Galactose-Induced Accelerated Aging Model.

This work presents a semi-quantitative spectroscopic approach, including FTIR-ATR and Raman spectroscopies, for the biochemical analysis of red blood cells (RBCs) supported by the biochemical, morphological and rheological reference techniques. This multi-modal approach provided the description of the RBC alterations at the molecular level in a model of accelerated aging induced by administration of D-galactose (D-gal), in comparison to natural aging. Such an approach allowed to conclude that most age-related biochemical RBC membrane changes (a decrease in lipid unsaturation and the level of phospholipids, or an increase in acyl chain shortening) as well as alterations in the morphological parameters and RBC deformability are well reflected in the D-gal model of accelerated aging. Similarly, as in natural aging, a decrease in LDL level in blood plasma and no changes in the fraction of glucose, creatinine, total cholesterol, HDL, iron, or triglycerides were observed during the course of accelerated aging. Contrary to natural aging, the D-gal model led to an increase in cholesterol esters and the fraction of total esterified lipids in RBC membranes, and evoked significant changes in the secondary structure of the membrane proteins. Moreover, a significant decrease in the phosphorous level of blood plasma was specific for the D-gal model. On the other hand, natural aging induced stronger changes in the secondary structures of the proteins of the RBCs' interior. This work proves that research on the aging mechanism, especially in circulation-related diseases, should employ the D-gal model with caution. Nonetheless, the D-gal model enables to imitate age-related rheological alterations in RBCs, although they are partially derived from different changes observed in the RBC membrane at the molecular level.

Drugs for preventing red blood cell dehydration in people with sickle cell disease.

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. This is an updated version of a previously published review. OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We also searched online trials registries for any ongoing trials (01 July 2018).Last search of the Group's Haemoglobinopathies Trials Register: 08 October 2018. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies for inclusion, assessed study quality and extracted data. MAIN RESULTS: Of the 51 studies identified, three met the inclusion criteria, including 524 people with sickle cell disease aged between 12 and 65 years of age. One study tested the effectiveness of zinc sulphate as compared to placebo and the remaining two assessed senicapoc versus placebo. No deaths were seen in any of the studies (low-quality evidence). The zinc sulphate study showed a significant reduction in painful crises (in a total of 145 participants) over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15) (moderate-quality evidence). However, analysis was restricted due to limited statistical data. Changes to red blood cell parameters and blood counts were inconsistent (very low-quality evidence). No serious adverse events were noted in the study. The Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo showed that the high dose senicapoc showed significant improvement in change in hemoglobin level, the number and proportion of dense red blood cells, red blood cell count and indices and hematocrit value (very low-quality evidence). The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups (low-quality evidence). A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises. AUTHORS' CONCLUSIONS: While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red blood cell survival (depending on dose), this did not lead to fewer painful crises.Given this is no longer an active area of research, this review will no longer be regularly updated.

Drugs for preventing red blood cell dehydration in people with sickle cell disease.

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. This is an updated version of a previously published review. OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials Register: 28 November 2015. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies for inclusion, assessed study quality and extracted data. MAIN RESULTS: Of the 51 studies identified, three met the inclusion criteria. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups. A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises. AUTHORS' CONCLUSIONS: While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red cell survival (depending on dose), this did not lead to fewer painful crises.We will continue to run searches to identify any potentially relevant trials; however, we do not plan to update other sections of the review until new trials are published.

Vitamin D-Rich Diet in Mice Modulates Erythrocyte Survival.

BACKGROUND/AIMS: Epidemiological evidence suggests that vitamin D deficiency is associated with anemia. The potent metabolite 1,25(OH)2 vitamin D3 [1,25(OH)2D3] activates various signaling cascades regulating a myriad of cellular functions including suicidal cell death or apoptosis. Suicidal death of erythrocytes or eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine (PS) externalization. Stimulation of eryptosis may limit lifespan of circulating erythrocytes and thus cause anemia. In the present study, we explored the effect of a high vitamin D diet (10,000 I.U. vitamin D for 14 days) in mice on eryptosis. METHODS: Plasma concentrations of erythropoietin were estimated using an immunoassay kit, blood count using an electronic hematology particle counter, relative reticulocyte numbers using Retic-COUNT® reagent, PS exposure at the cell surface from annexin V binding, cell volume from forward scatter, and cytosolic Ca(2+) ([Ca(2+)]i) from Fluo3-fluorescence in FACS analysis. RESULTS: Vitamin D treatment decreased mean corpuscular volume, reticulocyte count, and plasma erythropoietin levels. Vitamin D treatment slightly but significantly decreased forward scatter but did not significantly modify spontaneous PS exposure and [Ca(2+)]i of freshly drawn erythrocytes. Vitamin D treatment augmented the stimulation of PS exposure and cell shrinkage following exposure to hyperosmotic shock (addition of 550 mM sucrose) or energy depletion (glucose removal) without significantly modifying [Ca(2+)]i. CONCLUSIONS: The present observations point to a subtle effect of exogenous vitamin D supplementation on erythrocyte survival.

Mechanical clearance of red blood cells by the human spleen: Potential therapeutic applications of a biomimetic RBC filtration method.

During their lifespan, circulating RBC are frequently checked for their deformability. This mechanical quality control operates essentially in the human spleen. RBC unable to squeeze though narrow splenic slits are retained and cleared from the blood circulation. Under physiological conditions this prevents microvessels from being clogged by senescent, rigid RBC. Retention of poorly deformable RBC is an important determinant of pathogenesis in malaria and may also impact the clinical benefit of transfusion. Modulating the splenic retention of RBC has already been proposed to support therapeutic approaches in these research fields. To this aim, the development of microplates for high throughput filtration of RBC through microsphere layers (microplate-based microsphiltration) has been undertaken. This review focuses on potential therapeutic applications provided by this technology in malaria chemotherapy and transfusion.

Drugs for preventing red blood cell dehydration in people with sickle cell disease.

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials Register: 25 October 2011. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies for inclusion, assessed study quality and extracted data. MAIN RESULTS: Of the 51 studies identified, three met the inclusion criteria. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups. A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises. AUTHORS' CONCLUSIONS: While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red cell survival (depending on dose), this did not lead to fewer painful crises.

Red blood cell survival in long-term dialysis patients.

BACKGROUND: Shortening of red blood cell (RBC) survival contributes to the anemia of chronic kidney disease. The toxic uremic environment accounts for the decreased RBC life span. The contribution of mechanical damage caused by hemodialysis to the shortened life span is unclear. Reductions up to 70% in RBC survival have been reported in uremic patients. To date, no accurate well-controlled RBC survival data exist in dialysis patients treated using different dialysis modalities and receiving erythropoiesis-stimulating agent (ESA) therapy. The aim of this study was to determine RBC survival in hemodialysis (HD) and peritoneal dialysis (PD) patients compared with healthy persons. STUDY DESIGN: Observational study. SETTING & PARTICIPANTS: 14 HD patients and 5 PD patients were recruited from the dialysis unit. Healthy volunteers (n = 14) age- and sex-matched to HD participants were included. All dialysis patients received either ESA therapy or regular iron supplementation. PREDICTOR: Dialysis patients versus age- and sex-matched healthy controls. OUTCOMES: RBC survival. MEASUREMENTS: RBC survival was determined using radioactive chromium labeling. RESULTS: More than 85% of dialysis patients were anemic (hemoglobin, 12.0 ± 1.1 g/dL); hemoglobin concentrations were not significantly different between HD and PD patients. Median RBC survival was significantly decreased by 20% in HD patients compared with healthy controls: 58.1 (25th-75th percentile, 54.6-71.2) versus 72.9 (25th-75th percentile, 63.4-87.8) days (P = 0.02). No difference was shown between the PD and HD groups: 55.3 (25th-75th percentile, 49.0-60.2) versus 58.1 (25th-75th percentile, 54.6-71.2) days (P = 0.2). LIMITATIONS: Label loss from RBCs associated with the chromium 51 labeling technique needs to be accounted for in the interpretation of RBC survival data. CONCLUSIONS: Despite current ESA therapy, decreased RBC survival contributes to chronic kidney disease-related anemia, although the reduction is less than previously reported. There does not appear to be net mechanical damage associated with HD therapy resulting in decreased RBC life span.

Hemolysis and survival of autologous red blood cells salvaged after cemented and uncemented total hip arthroplasty.

Autotransfusion is widely used after total hip arthroplasty (THA), but there are concerns about damage of red blood cells (RBCs) collected after surgery. In this study, we wanted to determine the damage and survival of RBCs salvaged after cemented THA and after uncemented THA and to compare the results. In this prospective study of 60 patients-30 who underwent cemented THA and 30 who underwent uncemented THA-postoperative autotransfusion systems (BIODREN; B.E.R.C.O., Modena, Italy) were used. Levels of potassium and free hemoglobin in the postoperative blood samples were analyzed. Before transfusion, salvaged RBCs were labeled with radioactive chromium-51, and their survival was measured. In blood salvaged after cemented THA, medium potassium level was 4.1 mmol/L (range, 3.2-5.6 mmol/L), and mean free hemoglobin level was 327 mg% (range, 120-410 mg%). In blood salvaged after uncemented THA, mean potassium level was 4.2 mmol/L (range, 3.1-5.5 mmol/L), and mean free hemoglobin level was 296 mg% (range, 130-402 mg%). In the cemented group, RBC survival was 73% at 48 hours after transfusion (range, 61%-79%), and mean time from 100% activity to 50% activity was 21 days (range, 14.2-28.2 days). In the uncemented group, RBC survival was 75% at 48 hours after transfusion (range, 68%-82%), and mean time from 100% to 50% activity of radio-labeled RBCs was 22 days (range, 16.2-29.4 days). There were no statistically significant differences in potassium levels, free hemoglobin levels, or RBC survival between the cemented and uncemented groups. Blood salvaged after surgery was not significantly damaged. Our study results confirmed that washing blood collected after surgery is not necessary. Not washing this blood is safe and decreases allogeneic transfusion in orthopedic procedures.

Drugs for preventing red blood cell dehydration in people with sickle cell disease.

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials Register: 22 May 2009. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies for inclusion, assessed study quality and extracted data. MAIN RESULTS: Of the 47 studies identified, two met the inclusion criteria. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups. A subsequent Phase III study had to be stopped prematurely due to lack of reduction in the number of painful crisis. AUTHORS' CONCLUSIONS: While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicentre studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.Though the phase II study of senicapoc showed that the drug improved red cell survival, depending on dose, this did not lead to fewer painful crises; a subsequent phase III study was terminated prematurely for this reason.

Clinical relevance of anemia and transfusion iron overload in myelodysplastic syndromes.

Most patients with myelodysplastic syndrome eventually become dependent on regular red cell transfusions. This dependency has a negative impact on clinical outcome, primarily because it may be associated with more severe marrow failure. In addition, however, transfusion dependency may involve clinical consequences of chronic anemia and iron overload. Although transfusion iron is primarily taken up by the reticuloendothelial cells, the metal is later redistributed to parenchymal cells. This redistribution is modulated by several factors, including the degree of ineffective erythropoiesis through its suppressive effect on hepcidin production. Body iron status is routinely assessed by serum ferritin and transferrin saturation, but there is a need of reliable tools for locating iron accumulation in patients. Magnetic resonance imaging T2* provides a non-invasive method for detecting and quantifying both liver and myocardial iron overload. Clinical consequences of parenchymal iron overload have been reported not only in thalassemia major, but also in patients with myelodysplastic syndrome. Transfusion-dependent patients with isolated erythroid dysplasia and low risk of leukemic evolution are more likely to develop parenchymal iron overload and its toxicity, and therefore may benefit from chelation therapy. There may also be a benefit of chelation therapy in patients with transfusion iron overload undergoing allogeneic stem cell transplantation. Deferoxamine and deferasirox are currently available for treatment of transfusion iron overload in patients with myelodysplastic syndrome.

The 24-hour posttransfusion survival of baboon red blood cells preserved in citrate phosphate dextrose/ ADSOL (CPD/AS-1) for 49 days.

The purpose of this study was to evaluate the baboon as an animal model for evaluating red blood cell (RBC) preservation by comparing the 24-h posttransfusion survival of baboon RBCs preserved in citrate phosphate dextrose/ADSOL (CPD/AS-1) solution at 4 degrees C for 49 days to that of human RBCs preserved under similar conditions. CPD/AS-1 originally was approved by the Food and Drug Administration for 49-day storage of RBCs, but this period subsequently was reduced to 42 days. Adult male baboons (Papio anubis and P. cynocephalus) were autotransfused with RBCs that had been harvested using CPD and that had been resuspended and stored in AS-1 solution at 4 degrees C for as long as 49 days. The 24-h posttransfusion survival was measured using the 51Cr/125I-albumin method. The 24-h posttransfusion survival (mean +/- standard deviation) was 74% +/- 7% for seven units of CPD/AS-1-treated RBCs stored for 35 days, 65% +/- 15% for 12 units stored for 42 days, and 43% +/- 16% for seven units stored for 49 days. The mean 24-h posttransfusion survival rate for autologous baboon RBCs stored in CPD/AS-1 at 4 degrees C for 35 days (74%) was similar to that for autologous human RBCs stored in a similar manner. Further storage for 42 and 49 days resulted in lower values for baboon RBCs compared with human RBCs.

The red cell revisited--matters of life and death.

An erythrocyte-fractionating method combining volume and subsequent density separation is described. Iron isotope (59Fe)-validation proved this combination of methods to be complementary. By deploying HbA1c as cell age marker, obtained fractions demonstrated that circulating erythrocytes lose 20% of hemoglobin and membrane by shedding vesicles. Vesiculation from older cells proved to be facilitated by the spleen. Animal studies revealed that such vesicles are rapidly removed from the circulation by scavenger receptors on Kupffer cells with phosphatidylserine acting as the principal ligand. These studies reveal the existence of an alternative pathway of erythrocyte breakdown. This means that the premortal substrate of 20% of any erythrocyte is at our disposal. As this kind of vesiculation takes place during the entire erythrocyte lifespan, loss and sometimes reutilisation of marker substances limits the usefulness of isotope studies to the first half of the erythrocyte lifespan, thereby putting the dogmatic lifespan of 120 days into question. Furthermore, these studies add to the understanding of hemoglobin A1c (HbA1c) metabolism and the origin of the wide variation of erythrocyte parameters in peripheral blood. Removal of old erythrocytes from the circulation and from donor blood may open new ways into the treatment of both bilirubin and secondary iron overload.

Erythrocyte aging in sickle cell disease.

Physiological removal of old erythrocytes from the circulation by macrophages is initiated by binding of autologous IgG to senescent cell antigen (SCA). SCA is generated from the anion exchanger band 3. This process is accompanied by a number of alterations in the function and structure of band 3. We measured these aging-related parameters in erythrocytes from individuals with sickle cell anemia. Most sickle erythrocytes have characteristics that are also found in senescent normal erythrocytes, such as an increased density and considerable concentrations of cell-bound IgG. Together with the concomitant changes in structure and function of band 3, these data suggest that most sickle erythrocytes have undergone a process of accelerated aging. Preliminary results indicate that this process is reversed upon vitamin E supplementation. These data show that the erythrocyte aging paradigm may provide a useful conceptual framework for the study of the pathophysiology and the evalution of therapeutic intervention in sickle cell disease, and support the view that oxidation can generate neoantigens that are recognized by autoantibodies.

Intraoperative blood salvage during cesarean delivery in a patient with beta thalassemia intermedia.

UNLABELLED: In this case report, we report a patient with a placenta accreta and thalassemia intermedia undergoing cesarean delivery. There are no data regarding the use of cell salvage in patients with thalassemia. During the course of her surgery, she lost approximately 9000 mL of blood. Of this blood, 2250 mL of concentrated red cells were collected, washed, and returned to the patient. During processing, increased hemolysis was noted in the effluent line of the cell salvage machine, which resolved by increasing the wash volume. The patient's postoperative course was uneventful. This case would suggest that cell salvage in patients with thalassemia can be performed safely; however, further study is warranted. IMPLICATIONS: This case report details the safe administration of cell salvage in a patient with beta thalassemia undergoing cesarean delivery. Cell salvage is the collection, washing, and re-administration of blood lost during surgery. This process has not been previously reported in a patient with this type of blood disease.

Comparison of radioisotope methods and a nonradioisotope method to measure the RBC volume and RBC survival in the baboon.

BACKGROUND: RBC volume, 24-hour posttransfusion survival, and life span can be measured with radio-isotopes and nonradioactive procedures. STUDY DESIGN AND METHODS: RBC volume was measured directly with autologous baboon RBCs labeled with biotin-X-N-hydroxysuccinimide (NHS), 51Cr, 99mTc, and 111In-oxine and indirectly from the 125I plasma volume and the total body Hct. Twenty-four-hour posttransfusion survival and life span were measured in autologous fresh baboon RBCs labeled with 51Cr, 111In-oxine, 99mTc, and biotin-X-NHS. RESULTS: Significantly larger RBC volumes were observed when the fresh autologous RBCs were labeled with 51Cr, 111In-oxine, or 99mTc than when they were labeled with the nonradioactive biotin-X-NHS. Twenty-four-hour posttransfusion survival values were significantly lower in the RBCs labeled with 111In-oxine or 99mTc than in the RBCs labeled with 51Cr. CONCLUSIONS: The greater in vivo elution of 51Cr, 111In-oxine, and 99mTc than that of biotin-X-NHS influenced the measurements of RBC volume, 24-hour posttransfusion survival, and life span of the fresh baboon RBCs.

Erythrocyte survival is promoted by plasma and suppressed by a Bak-derived BH3 peptide that interacts with membrane-associated Bcl-X(L).

Erythrocytes have a defined lifespan in vivo, and the signals that maintain their survival in circulation or trigger their death are unknown. Here, we investigated the control of erythrocyte survival and death in an in vitro culture system where erythrocytes survived for 10 days in serum-free medium in the presence or absence of bovine serum. Death of the cells in culture was correlated with increased exposure of phosphatidylserine and increased levels of intracellular calcium. Cell death could be suppressed by supplementing the medium with human plasma or serum, resulting in a doubling of the lifespan to 20 days. Freshly isolated erythrocytes and cultured erythrocytes were both found to express Bcl-X(L) and, to a lesser extent, Bak in membrane protein extracts. Treatment of the cells with a Bak-derived BH3 peptide fused to the internalization sequence of the antennapedia protein, which has previously been shown to enter cells by diffusion and antagonize Bcl-X(L), resulted in substantial cell death in erythrocyte cultures. BH3-induced death was accompanied by an immediate increase in accumulation of intracellular calcium and could be suppressed by plasma, but not by the caspase inhibitor zVAD. A BH3 peptide mutated at amino acid 78 of full-length Bak required for heterodimerization with Bcl-X(L) had no effect on cell viability or calcium levels. We conclude that the BH3 peptide accelerates erythrocyte death through antagonization of Bcl-X(L). The data suggest that erythrocyte survival is promoted by survival factors in plasma and by membrane-associated Bcl-X(L.)

Volume of RBCs, 24- and 48-hour posttransfusion survivals, and the lifespan of (51)Cr and biotin-X-N-hydroxysuccinimide (NHS)-labeled autologous baboon RBCs: effect of the anticoagulant and blood pH on (51)Cr and biotin-X-NHS elution in vivo.

BACKGROUND: The RBC injury that occurs during collection of the first few milliliters of blood into the pH 5.0 ACD (NIH, Formula A) is referred to as the lesion of collection. The RBC injury was evaluated by labeling the ACD RBCs with (51)Cr and measuring the 24-hour posttransfusion survival. The effect of the acidification of ACD blood on the in vivo elution of (51)Cr from the RBC has not been reported. STUDY DESIGN AND METHODS: Baboon blood was collected in heparin and in ACD and CP2D at different ratios of blood to anticoagulant. ACD blood with a pH of 5.7 to 6.9 was labeled with (51)Cr. Heparinized blood with a pH of 7.4 was labeled with biotin-X-N-hydroxysuccinimide (NHS). ACD blood with a pH of 5.9 was labeled with both (51)Cr and biotin-X-NHS. The RBC volumes, 24- and 48-hour posttransfusion survivals, and lifespans (T50) were measured. RESULTS: The RBC volume of ACD blood with a pH ranging from 5.7 to 6.9 was not affected by (51)Cr labeling. (51)Cr-labeled ACD blood with a pH of 6.9 had an RBC volume that was significantly greater than that seen in heparinized blood with a pH of 7.4 labeled with biotin-X-NHS. In vivo elution of (51)Cr from the RBCs prepared from the ACD blood with a pH of 5.7 to 6.9 and in vivo elution of biotin-X-NHS from RBCs prepared from ACD blood with a pH of 5.9 were associated with reductions in 24- and 48-hour posttransfusion survivals and T50. CONCLUSIONS: The anticoagulant and the pH of the medium in which the RBCs were labeled with (51)Cr or biotin-X-NHS affected in vivo elution of the label from the RBCs and may reduce posttransfusion survival values.

Erythrocyte viability in blood salvaged during total joint arthroplasty with cement.

BACKGROUND: Erythrocyte salvage, the collection of a patient's blood shed from the surgical wound, is one aspect of blood management. Previous investigators have examined salvaged blood for content; however, to our knowledge, none have examined the viability of erythrocytes after exposure to the chemical and thermal reactions produced by motorized instruments and polymethylmethacrylate during surgery. The purpose of this study was to determine the viability of salvaged erythrocytes from patients undergoing primary total joint arthroplasty with cement. METHODS: Erythrocyte viability studies were performed on specimens from three subjects with use of a double isotope-labeling technique employing chromium-51 and technetium-99m. With use of a fresh blood specimen obtained prior to surgery and a specimen of salvaged blood that had been recycled, washed, and filtered with use of the Cell Saver, the viability of the Cell-Saver-processed erythrocytes, labeled with chromium-51, was calculated on the basis of the technetium-99m-labeled red blood-cell mass. RESULTS: The mean erythrocyte viability (and standard deviation) in blood salvaged with use of the Cell Saver was 88.0% +/- 3.8%. The standard of the American Association of Blood Banks for minimum erythrocyte viability in adequately cross-matched allogeneic blood or predeposited autologous blood is 70%. CONCLUSIONS: The high rate of viability of the erythrocytes in this study shows that the Cell Saver is a valuable adjunct to other blood management techniques for patients having total joint arthroplasty. We believe that the very high mean rate of erythrocyte viability and the extremely small standard deviation in our three subjects, as compared with the standards of the American Association of Blood Banks, made additional study subjects unnecessary.

Green tea extract and aged garlic extract inhibit anion transport and sickle cell dehydration in vitro.

Both green tea extract (GTE or tea polyphenols) and aged garlic extract (AGE) effectively inhibited in vitro dehydration of sickle red blood cells induced by K-Cl cotransport or red cell storage. For K-Cl cotransport induced by 500 mM urea, 0.3 mg/ml EGCg (epigallocatechin gallate; a major component in GTE) almost completely inhibited dehydration, and 6 mg/ml AGE inhibited dehydration to 30% of the control level. Both vitamins E and C had no effect at the level of 2 mM. Different tea extracts had different degrees of inhibition, but the inhibitory activity increased when the number of hydroxyl groups in the compounds increased. With storage of sickle cells at 4 degrees C for 6 days, the cells started to undergo spontaneous dehydration when incubated at 37 degrees C. Neither inhibitors for Ca-induced K efflux nor K-Cl cotransport could inhibit cell dehydration of stored sickle cells, but both GTE and AGE effectively inhibited it. Chloride efflux measurements using a chloride electrode demonstrated that both GTE and AGE inhibited anion transport in red blood cells. The inhibitory mechanism of these compounds may be related to anion transport inhibition, although involvement of their antioxidant activities can not yet be ruled out.